摘要
采用数值计算和实验验证相结合的方法研究液固脉冲流化床中浓度波的传播和衰减. 当脉冲开半周期T2和闭半周期T1都远大于颗粒弛豫时间tp时,两相的惯性力之差在一个周期的绝大部分时间中相对于重力很小,可忽略,这时由双流体模型的动量方程可推导出推广的RichardsonZaki公式,双流体模型简化为局部平衡模型. 采用五阶精度WENO格式求解浓度波传播方程,得到了脉冲流化过程中浓度波传播与衰减的规律,与实验结果符合良好.
The propagation and decay of concentration wave in liquidsolid pulsed fluidized beds is studied by numerical simulation and experimental validation. When the semi-on period and semi-off period are much longer than the particle relaxation time, the difference between the inertia forces of the two phases is small compared with the gravity of the solid phases except a short period in the order of the particle relaxation time after a sudden change of fluidizing velocity, the momentum equations of the two phases in pulsed fluidized beds can be simplified to a local equilibrium model. The simulation difficulty caused by the ill-posedness of the basic two-fluid model can be avoided using the concentration wave equation. The liquidsolid flow pulsation induced by the fluidizing fluid varying in both sinusoidal and step-wise patterns is simulated using the five order WENO scheme for spatial derivative and three order TVD RungeKutta method for time derivative. The front-fixing method is used to handle the moving upper boundary. The simulation result of fluidizing velocity varying in step-wise pattern is validated and matches the experimental data well. In the pulsed fluidization, the concentration wave decays due to the interaction between the concentration discontinuity and dilatation waves.
出处
《过程工程学报》
CAS
CSCD
北大核心
2002年第5期392-399,共8页
The Chinese Journal of Process Engineering
基金
国家自然科学基金资助项目(编号: 10072669
10028103)
中国科学院过程工程研究所多相反应开放实验室资助项目
